• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.63-66
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• 2005

Six RC pier were tested under a constant axial load and a cyclically reversed horizontal load to investigate the performance of RC piers used in the high strength concrete and the high strength rebar. It is designed with a hollow section according to the Korean Bridge Design Standard. The variables of the test were concrete strength, rebar strength, a ratio of lap splice and a ratio of transvere rebar. The test results show that the performance of a RC Pier; failure mode, crack pattern, maximum load and ductility.

• Structural Engineering and Mechanics
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• v.24 no.3
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• pp.355-374
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• 2006

Thin walled steel bridge-piers/columns are vulnerable to damage, when subjected to earthquake excitations. Local buckling, global buckling or interaction between local and global buckling usually is the cause of this damage, which results in significant strength reduction of the member. In this study new innovative design concepts, "thin-walled corrugated steel columns" and "thin-walled cellular steel columns" are presented, which allow the column to undergo large plastic deformations without significant strength reduction; hence dissipate energy under cyclic loading. It is shown that, compared with the conventional designs, circular and stiffened box sections, these new innovative concepts might results in cost-effective designs, with improved buckling and ductility properties. Using a finite element model, that takes the non-linear material properties into consideration, it is shown that the corrugations will act like longitudinal stiffeners that are supporting each other, thus improving the buckling behavior and allowing for reduction of the overall wall thickness of the column.

• Earthquakes and Structures
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• v.25 no.2
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• pp.89-97
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• 2023

In order to obtain the impact of socket connection interface forms and socket gap sizes on the seismic performance of reinforced concrete (RC) socket prefabricated bridge piers, quasi-static tests for three socket prefabricated piers with different column-foundation connection interface forms and reserved socket gap sizes, as well as to the corresponding cast-in-situ reinforced concrete piers, were carried out. The influence of socket connection structure on various seismic performance indexes of socket prefabricated piers was studied by comparing and analyzing the hysteresis curve and skeleton curve obtained through the experiment. Results showed that the ultimate failure mode of the socket prefabricated pier with circumferential corrugated treatment at the connection interface was the closest to that of the monolithic pier, the maximum bearing capacity was slightly less than that of the cast-in-situ pier but larger than that of the socket pier with roughened connection interface, and the displacement ductility and accumulated energy consumption capacity were smaller than those of socket piers with roughened connection interface. The connection interface treatment form had less influence on the residual deformation of socket prefabricated bridge piers. With the increase in the reserved socket gap size between the precast pier column and the precast foundation, the bearing capacity of the prefabricated socket bridge pier component, as well as the ductility and residual displacement of the component, would be reduced and had unfavorable effect on the energy dissipation property of the bridge pier component.

• International Journal of Railway
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• v.3 no.1
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• pp.1-6
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• 2010

The steel plate-girder bridges with concrete gravity piers have possibilities of overturning by lateral inertial force which can be reproduced by sudden earthquake attack. This paper explores an overturning mechanism of existing concrete gravity pier onto the sandy soil in the event of lateral push-over load by in-situ experimental observation. The in-situ push-over experiment for pier with earth anchors between spread footing and rock beds exhibits a reasonable enhancement of ductility against overturning. In unanchored system, a flexural crack at cold joint of concrete pier is not developed because of the over-turning of the pier. This leads a global instability (rotation) of pier-footing system with relatively low stresses in pier itself. While a lateral load is persistently increased in anchored system, the successive flexural cracking failure at cold joint is observed even after the local shear failure of soil due to redistribution of stress equilibrium between soil and pier structure as long as a tensile action of anchor cable is active.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.04a
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• pp.341-348
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• 2000

The existing solid circular RC pier without seismic detailing is found to have poor ductility due to the premature bond failure of lap spliced longitudinal bars. The steel-jacket was introduced to prevent this unexpected type of failure. The nonlinear behavior and he seismic performance of the retrofitted pier were examined through the scale model test and compared with those of existing one. It is confirmed from the test results that the steel-jacket retrofitting can be used as an measure to improve seismic performance considerably.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.4
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• pp.17-24
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• 2010

The hollow RC(Reinforced concrete) pier has the merit of lightweight pier compared with solid RC pier. However, the hollow RC pier shows a low ductile behavior due to brittle failure of inside concrete. To overcome this problem, the internally confined hollow reinforced concrete column has been developed. In this study, the behavior of internally confined hollow RC piers were evaluated with safety ratio, ductility, total material cost, the total weight of the pier, etc. The chosen parameters for the study are hollow ratio, thickness of internal steel tube, intervals between vertical re-bars, numbers of horizontal re-bars, and strength of concrete. As a result of parameters study, the usage of a minimum necessary thickness of the internal steel tube is the most effective.

• Earthquakes and Structures
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• v.10 no.6
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• pp.1467-1486
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• 2016

This research focuses on seismic performance of a class of single pier skewed bridges with three different pier-deck connections; skew angles vary from $0^{\circ}$ to $60^{\circ}$. A well-documented four span continuous deck bridge has been modeled and verified. Seat-type connections with fixed and sliding bearings plus monolithic pier-deck connections are studied. Shear keys are considered either fully operational or ineffective. Seismic performances of the bridges and the structural components are investigated conducting bidirectional nonlinear time history analysis in OpenSees. Several global and intermediate engineering demand parameters (EDP) have been studied. On the basis of results, the values of demand parameters of skewed bridges, such as displacement and rotation of the deck plus plastic deformation and torsional demand of the piers, increase as the skew angle increases. In order to eliminate the deck collapse probability, the threshold skew angle is considered as $30^{\circ}$ in seat-type bridges. For bridges with skew angles greater than $30^{\circ}$, monolithic pier-deck connections should be applied. The functionality of shear keys is critical in preventing large displacements in the bearings. Pinned piers experience considerable ductility demand at the bottom.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.121-124
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• 2008

Fast construction of bridge substructures is a new trend of bridge design. A precast pier system with bonded prestressing bars was proposed. In this paper, quasi-static tests on precast prestressed piers were conducted to evaluate the seismic behavior of the precast piers with bonded prestressing bars. In order to strengthen the shear strength of the joints between column segments, steel tubes filled with mortar were used. Displacement ductility and energy dissipation capacity of the precast piers were evaluated. The suggested precast pier system showed better seismic performance than the required ductility. Based on the research results, an example bridge pier for light-railway lines was designed and design considerations were discussed.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.10a
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• pp.432-439
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• 2000

According as ground acceleration becomes to exceed gravity acceleration recently, design is impossible or economical efficiency is poor in existing seismic design method. So increase of seismic isolated bridges is currently in progress. However, because base isolation design method is developed in high seismic regions. it may not be compatible in Korea. Therefore, this research has objective to evaluate ductility of pier and response modification factor according to the ductility of pier in seismic isolated bridges and to adapt to seismic characteristics in Korea. For this purpose, nonlinear analysis is accomplished with so many time histories derived from spectral density function compatible with response spectrum described in the design code and base isolation system modeled linear system, bi-linear system, and friction system. Through application of the proposed method, we had result that it may be compatible that response modification factor for the seismic isolated bridges is smaller than half of that for the conventional bridges when natural period of structures exceeds proper level.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2005.03a
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• pp.372-379
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• 2005

The earthquake resistant design concept allows the nonlinear behavior of structures under the design earthquake. Therefore the response spectrum method provided in most codes introduces the response modification factors to consider the nonlinear behavior in the design process. For bridges, the response modification factors are given according to the ductility as well as the redundancy of piers. In this study, among influence factors on the nonlinear seismic behavior, the randomness of artificial accelerograms simulated with different durations, the pier ductility represented by the inelastic behavior characteristic curve and the regularity represented by pier heights are selected. The influence of such factor on the seismic behavior is investigated by comparing response modification factors calculated with the nonlinear time step analysis.